The invention relates to an endless cable winch, in particular for a service lift, in particular for wind power plants, comprising a working cable and a safety cable, a driving cable pulley around at least a part of which the working cable is wrapped, a drive for driving the driving cable pulley, and further comprising a safety device for the safety cable.
Endless cable winches (also called “hoists”) of this type are widely used for person transport applications. It is generally the case here that a lift cage, a platform or the like for receiving one or more persons is moved in an upward or downward direction by means of the endless cable winch along a cable depending from a building or the like. To provide a fall arrestor in the event of a cable breakage of the working cable or in the event of a gearbox failure of the endless cable winch, the safety cable is provided which runs jointly with and independently of the working cable and which, if the safety cable moves downward at too high a speed, generates a blocking action at the safety device, such that the safety cable is abruptly halted and the lift cage, the platform etc. is caught.
The abrupt braking in the event of failure of the working cable however results in a high load being exerted on the safety cable, and furthermore, the persons situated in the lifting device moved by the cable winch are subjected to intense physical and psychological stress.